Well, Reagent Restocker is under the MIT license, so they are free to do so in my particular case, and I'm actually powerless legally to do much except claim ownership, thanks to MIT being a very liberal license. I have not checked the licenses of other addons. I'll take a look after work today.

Can you point me to a thread where this is being discussed?

EDIT: If you can provide a link or other evidence of your claim that they "freely admit that they have no legal right to do it," I will pull all of my endorsements ASAP. I do not tolerate breaking the law, especially knowingly.